Generally, a cooking apparatus is an appliance to cook food using a gas or electricity. Such a cooking apparatus includes an operating unit to operate the same, and a variety of settings and operations of the cooking apparatus can be performed by the operating unit.
Recently, a variety of foods can be cooked using the cooking apparatus, so that a structure of the operating unit capable of setting and operating a variety of functions is under the development.
Typically, the Korean Patent Laid-Open No. 10-2009-0082624 discloses a cooking apparatus in which a touch-type control panel is provided and a variety of functions can be set and operated by touch. Further, the control panel of the cooking apparatus has a structure in which a touch operated capacitive keypad is arranged on the rear side of a glass panel.
Further, the U.S. Pat. No. 5,995,877 discloses a control unit in which a film having a piezo-sensor built in the rear side of a plane-shaped control surface is provided and the film is connected to a printed circuit board through a connector to enable an operation signal to be inputted when a user operates the control surface.
There are problems in such conventional technologies that a sensor, a keypad having a sensor attached thereto or a film should be attached to a precise position on an operational surface to make a precise recognition when operated by a user, and a bad recognition occurs when they are not attached to the precise position.